Peugeot 307

A Peugeot 307 question from Victoria Morgan

My Peugeot 307 hdi is blowing out a massive amount of white smoke from the exhaust and it smells like burning. Someone mentioned that my turbo had probably gone. Is this right? I assumed my turbo had gone months ago as it stopped kicking in and the car just struggled to pick up speed, but we have just carried on not really seeing it as much of a problem. But now this has started happening. Can anyone please help?